The present invention relates to improved water containing aerosol coatings.
There are several prior publications which disclose water reducible coatings, and some in particular which describe water reducible aerosol coatings. Although water reducible aerosol coatings have been taught, the inclusion of large amounts of water in water reducible aerosol coating formulations containing water soluble resins has been contraindicated.
Belgium Pat. No. 880272 to The Conn Chem Group, Limited, discloses a water reducible aerosol paint which includes an "insoluble" film forming acrylic polymer and a "sufficient amount of a surfactant to keep the solids in suspension in the liquid phase." The present invention utilizes water soluble resins and therefore does not require the use of surfactants. Unlike the resin emulsion of the Conn Chem invention, the resin in the present invention is uniformly dispersed as a single phase throughout the solvent in essentially molecular dimensions. This results in coatings having higher gloss.
U.S. Pat. No. 4,125,499 to Jerold D. Howard describes a water-receptive paint which contains a maximum of 8 weight percent water. Howard teaches, in part, "It is preferable to eliminate entirely the presence of water, as it performs no useful function in the formulation, but represents some source of can corrosion and instability." (see column 3, lines 41-44). In the present invention water comprises a substantial part of the coating's solvent phase. Can corrosion is substantially reduced by using commercially available lined cans and by adjusting the pH of the formulation to greater than 8. The stability of the present coatings is dependent upon the resin utilized, and is comparable to currently available water based brush-on paints made with similar resins.
The present invention provides a water reducible aerosol coating which comprises a single phase liquid system and utilizes water as a cosolvent. There is no need to use defoamers or surfactants which contribute to water sensitivity of the resultant film; in fact, the presence of defoamers in the present invention may cause foaming. The present coatings are environmentally safe, non-flammable and may be cleaned up with water.